title: Femtosecond crystallographic experiment in wide-bandgap LiF crystal.
abstract: We report a femtosecond crystallographic study of the dependence of the free-carries generation to the alignment of a crystalline sample to the laser polarization. The probe pulse transmission exhibits a π/2 modulation that is shown to be correlated with the direction dependence of the effective electron mass. This observation suggests that nonlinear ionization is the first channel for free electron generation during the laser pulse. Moreover, the temporal evolution of the probe pulse transmission indicates the dominance of the avalanche ionization and that nonlinear ionization provides the initial seed electrons for avalanche."
authors.affiliation: Molekül und Oberflächenphysik, Fakultät für Physik, Universität Bielefeld, 33615 Bielefeld, Germany. dachraoui@physik.uni-bielefeld.de
authors.forename: Hatem
authors.initials: H
authors.lastname: Dachraoui
authors.forename: Christian
authors.initials: C
authors.lastname: Oberer
authors.forename: Ulrich
authors.initials: U
authors.lastname: Heinzmann
mesh_terms: D003461:Crystallography / Q000379:methods*; D005459:Fluorides / Q000737:chemistry*; D008027:Light; D018020:Lithium Compounds / Q000737:chemistry*; D012031:Refractometry / Q000379:methods*; D012542:Scattering, Radiation
chemical_list: D018020:Lithium Compounds; C027651:lithium fluoride; D005459:Fluorides